Cruise Control: Description and Operation

When the ignition switch is in the ON or START position, power is supplied:
^ through 10 A fuse (No. (26) ,located in the fuse block)
^ to Automatic Speed Control Device (ASCD) cancel switch terminal (1) (A/T models)
^ with brake pedal released, power remains supplied through ASCD cancel switch terminal (2) (A/T models) and
^ to ASCD hold relay terminal (7) (A/T models)
^ through 10 A fuse (No. (26) located in the fuse block)
^ to ASCD main switch terminal (1) and
^ to ASCD hold relay terminal (5) (M/T models) or
^ to ASCD hold relay terminal (5) (A/T models).
When ASCD main switch is in the ON position, power is supplied:
^ from terminal (2) of the ASCD main switch
^ to ASCD control unit terminal (4) and
^ from terminal (4) of the ASCD main switch
^ to ASCD hold relay terminal (1) (M/T models) or
^ to ASCD hold relay terminal (1) (A/T models).
Ground is supplied:
^ to ASCD hold relay terminal (2) (M/T models) or
^ to ASCD hold relay terminal (2 (A/T models).
^ through body grounds (E12) and (E37).
With power and ground supplied, the ASCD hold relay is activated, and power is supplied:
^ from terminal (3) of the ASCD hold relay (M/T or A/T models)
^ to ASCD control unit terminal (4) and
^ to ASCD clutch pedal position switch terminal (1) (M/T models) or
^ from terminal (6) of the ASCD hold relay (A/T models)
^ to inhibitor relay terminal (3) (A/T models).
Power remains supplied to ASCD control unit terminal (4) when the ASCD main switch is released to the N (neutral) position.
Ground is supplied:
^ to ASCD control unit terminal (3)
^ through body grounds (M51), (M76) and (M77)

Inputs
At this point, the system is ready to activate or deactivate, based on inputs from the following:
^ speedometer in the combination meter
^ stop lamp switch
^ ASCD steering switch
^ inhibitor relay (A/T models)
^ ASCD cancel switch (on clutch pedal) (M/T models)
^ ASCD cancel switch.
A vehicle speed input is supplied:
^ to ASCD control unit terminal (7)
^ from terminal (5) of the combination meter.
Power is supplied at all times:
^ to stop lamp switch terminal (1)
^ through 15 A fuse (No. (18) ,located in the fuse block).
When the brake pedal is depressed, power is supplied:
^ from terminal (2) of the stop lamp switch
^ to ASCD control unit terminal (11).
Power is supplied at all times:
^ through 10 A fuse (No. (35) located in the fusible link and fuse box)
^ to horn relay terminal (1)
^ through terminal (1) of the horn relay
^ to ASCD steering switch terminal (12).
When the SET/COAST button is depressed, power is supplied:
^ from terminal (14) of the ASCD steering switch
^ to ASCD control unit terminal (2).
When the RESUME/ACCEL button is depressed power is supplied:
^ from terminal (13) of the ASCD steering switch
^ to ASCD control unit terminal (1).
When the CANCEL button is depressed, power is supplied:
^ to ASCD control unit terminals (1) and (2)
When the system is activated, power is supplied:
^ to ASCD control unit terminal (5)
Power is interrupted when:
^ the shift lever is placed in P or N (A/T models)
^ the clutch pedal is depressed (M/T models) or
^ the brake pedal is depressed.

Outputs
The ASCD actuator controls the throttle drum via the ASCD wire based on inputs from the ASCD control unit. The ASCD pump consists of a vacuum motor, an air valve, and a release valve.
Power is supplied:
^ from terminal (8) of the ASCD control unit
^ to ASCD pump terminal (1).
Ground is supplied to the vacuum motor:
^ from terminal (9) of the ASCD control unit
^ to ASCD pump terminal (4)
Ground is supplied to the air valve:
^ from terminal Go of the ASCD control unit
^ to ASCD pump terminal (4).
Ground is supplied to the release valve:
^ from terminal (14) of the ASCD control unit
^ to ASCD pump terminal (3).
When the system is activated, power is supplied:
^ from terminal (13) of the ASCD control unit
^ to combination meter terminal (25) and
^ to A/T control unit terminal (37) (A/T models).
Ground is supplied:
^ to combination meter terminal (27)
^ through body grounds (M51), (M76) and (M77)
With power and ground supplied, the CRUISE indicator illuminates.
When vehicle speed is approximately 8 kph (5 mph) below Set speed on Apr models, ground is supplied:
^ from terminal (12) of the ASCD control unit
^ to ASCD control unit terminal (40).
When this occurs, the A/T control unit cancels overdrive.
When vehicle speed reaches approximately 3 kph (2 mph) above set speed, overdrive is reactivated.